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Edit Spice simulation model of TLV2772 operational amilifer to work on single supply not dual supply

Hello Guys,

I'm using the TLV2772 and the TLV2774 operational amplifiers in my electronics circuit to construct low pass, high-pass and notch filter.

They are supposed to work using single supply i.e. +5V and Ground (no -ve supply required), however, the Simulation Models which I got from the TI website which you can download here http://www.ti.com/litv/zip/sloj019 works perfectly on the MultiSim 11.0 software (by National Instruments) only when using dual supply only (i.e. I have to connect it using +5 and -5 for it to work correctly).

Here is the simulation model for easy reach and view
* TLV2772 operational amplifier "macromodel" subcircuit
* created using Parts release 8.0 on 12/12/97 at 10:08
* Parts is a MicroSim product.
* connections:   non-inverting input
*                | inverting input
*                | | positive power supply
*                | | | negative power supply
*                | | | | output
*                | | | | |
.subckt TLV2772  1 2 3 4 5
  c1   11 12 2.8868E-12
  c2    6  7 10.000E-12
  css  10 99 2.6302E-12
  dc    5 53 dy
  de   54  5 dy
  dlp  90 91 dx
  dln  92 90 dx
  dp    4  3 dx
  egnd 99  0 poly(2) (3,0) (4,0) 0 .5 .5
  fb    7 99 poly(5) vb vc ve vlp vln 0 15.513E6 -1E3 1E3 16E6 -16E6
  ga    6  0 11 12 188.50E-6
  gcm   0  6 10 99 9.4472E-9
  iss   3 10 dc 145.50E-6
  hlim 90  0 vlim 1K
  j1   11  2 10 jx1
  j2   12  1 10 jx2
  r2    6  9 100.00E3
  rd1   4 11 5.3052E3
  rd2   4 12 5.3052E3
  ro1   8  5 17.140
  ro2   7 99 17.140
  rp    3  4 4.5455E3
  rss  10 99 1.3746E6
  vb    9  0 dc 0
  vc    3 53 dc .82001
  ve   54  4 dc .82001
  vlim  7  8 dc 0
  vlp  91  0 dc 47
  vln   0 92 dc 47
.model dx D(Is=800.00E-18)
.model dy D(Is=800.00E-18 Rs=1m Cjo=10p)
.model jx1 PJF(Is=2.2500E-12 Beta=244.20E-6 Vto=-.99765)
.model jx2 PJF(Is=1.7500E-12 Beta=244.20E-6 Vto=-1.002350)

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How can I edit it so that the device works perfectly without -5, rather Ground be used. I didn't test the real device yet, but on reality will it work with single supply or will it need -5 V ??

Please help.
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1 Solution
adkryAuthor Commented:
Hello, Guys if there is something you don't understand I can explain, please ask if you have any queries just don't leave the question empty like that, I wasn't asking myself LOL
Hi - I am not too sure about modifying the model definition above.  

However, I think you will need to provide a reference voltage somewhere near 2.5 V in order to be able to bias the input FETs into their linear range. This will form a fake "ground" for your AC signals, with the op-amp operating as usual, but with effective power supply voltages of +/- 2.5V.  Which are really +5 and 0.

There is a sample circuit where they accomplish this in Figure 62 of the datasheet. They indicate running the op-amp using a 3V supply, with a 1.23V level as the fake ground.

Then I think you just connect the spice model's "negative power supply" node to gnd (i.e. 0V) and the "positive power supply" to +5.

adkryAuthor Commented:

Thank you for your answer and help.

I've checked Figure 62 in the datasheet, I didn't quite get the aim. The TLV2772 should work fine with single supply (shouldn't it?) i.e. just connect +5 V to Vdd and 0V to Vss and it should all work fine.

Do you think the problem is not in the simulation model ? Is the problem in my circuit ? Here's a screenshot of my circuit
my circuit
Please advise and be elaborate in your answer.
adkryAuthor Commented:
Hello Algorith, can you help me with this question as well please http://www.experts-exchange.com/Hardware/Misc/Q_27465862.html#37333425
adkryAuthor Commented:
Thanks the simulation is fine, I just need virtual ground
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